Glass coated with heat reflecting colored film and process for its production

ABSTRACT

A glass coated with a heat reflecting colored film, which is excellent in the uniformity of the film thickness and composition, which is free from a unfavorable whitish coloration in ceramic color printing and which is excellent in a silver print coloration, is presented. A glass coated with a heat reflecting colored film, obtained by heat treatment of a glass having a first layer containing iron oxide, chromium oxide and nickel oxide and a second layer containing cobalt oxide, laminated sequentially by a sputtering method, on one side of a glass substrate.

TECHNICAL FIELD

[0001] The present invention relates to a glass coated with a heatreflecting colored film and a process for its production.

BACKGROUND ART

[0002] In recent years, it has become common to employ a heat reflectingglass having a low solar energy transmittance (a ratio of directlytransmitting energy to incident solar energy) as a means to increasecooling efficiency of e.g. a vehicle such as an automobile. As a methodto reduce the solar energy transmittance, a method of employing acolored glass or a method of coating a colored film which is excellentin the heat reflecting performance on a transparent soda lime glass oron a colored glass having a high transmittance, is available. The lattermethod is preferred from the viewpoint of the heat reflectingperformance and recycling of the glass.

[0003] What are required for such a glass coated with a heat reflectingcolored film, may, for example, be that the solar energy transmittanceis low, the visible light transmittance is high as compared with thesolar energy transmittance, it has sufficient durability for use fore.g. vehicles, it has a color tone which does not impair the design ofe.g. vehicles, and it has a high sheet resistance. As a glass coatedwith a heat reflecting colored film which satisfies these requirements,a glass is known wherein an oxide film comprising cobalt oxide as themain component, at least 10 mass % (the ratio based on the total metalamount, the same applies hereinafter) of iron and at least 5 mass % ofchromium, is formed in a thickness of from 10 to 50 nm by a sprayingmethod.

[0004] However, such a glass has had a problem such that the filmthickness, composition, etc. are non-uniform, and the yield is poor.

[0005] It is known in literatures to obtain, by a sputtering method, aglass having a film formed which comprises cobalt oxide as the maincomponent and at least 5 mass % of iron oxide. For example, JP-A-9-30837discloses a heat reflecting glass having a coating film of metal oxidesformed with a metal composition such that cobalt: 65 to 96 mass %,chromium: 2 to 25 mass %, iron: 2 to 33 mass %, and a sputtering methodis mentioned as a method for forming such a coating film.

[0006] However, in a magnetron sputtering method whereby thefilm-forming speed is remarkably higher than the conventional methods,which is suitable for a mass production of a film having uniform filmthickness and composition and which is a sputtering method presentlyutilized industrially, an alloy target comprising cobalt and iron cannot be practically used, since such an alloy target is a ferromagneticmaterial, whereby a magnetic flux of magnetron is hardly formed over thetarget surface. In the above publication, no specific disclosure isgiven with respect to a sputtering method, and only a spraying method isspecifically described.

[0007] Heretofore, it has been common that a ceramic paste having aceramic color composition formed into a paste, is screen-printed alongthe peripheral portion or the center portion of a window glass of anautomobile, followed by drying and baking in a bending step. Such aceramic color paste is baked e.g. along the peripheral portion of glassto form a colored opaque layer and thereby to be used for preventingdeterioration of an adhesive by ultraviolet rays or to prevent thebonded portion from being seen through from outside the car. As such aceramic color composition, one having a heat resistant coloring pigmentmixed to a glass frit, is known and usually has a color tone of a blackcolor or a dark gray color. Such a composition is called a black ceramiccoating material.

[0008] However, when such a ceramic color paste is printed on a glasshaving formed by a spray method a conventional oxide film comprisingcobalt oxide as the main component, at least 10 mass % of iron and atleast 5 mass % of chromium, there has been a problem that unfavorablewhitish coloration is likely to result.

[0009] Further, when a glass is used as e.g. a rear glass of anautomobile, so-called silver printing is carried out, wherein a silverpaste which is an exothermic material to prevent fogging, is linearlyprinted and baked. However, a conventional glass having formed by aspray method an oxide film comprising cobalt oxide as the maincomponent, at least 10 mass % of iron and at least 5 mass % of chromium,has had a problem that coloration of this silver print is poor (suchthat it forms an antique red color).

[0010] Accordingly, the above-mentioned glass coated with a heatreflecting colored film, cannot practically be produced by means of amagnetron sputtering method, and the above-mentioned problems such asformation of non-uniformity in the case of the production by theabove-mentioned spray method, unfavorable whitish coloration in ceramiccolor printing, and poor coloration of silver printing, have not beensolved.

[0011] It is an object of the present invention to provide a glasscoated with a heat reflecting colored film, which can be produced by asputtering method, which is excellent in the uniformity of the filmthickness and composition and which is excellent in heat reflectivity,and a process for its production. Further, it is another object of thepresent invention to provide a glass coated with a heat reflectingcolored film, which is excellent in the uniformity of the film thicknessand composition, which is free from unfavorable whitish coloration inceramic color printing and which is excellent in coloration of silverprinting.

DISCLOSURE OF THE INVENTION

[0012] As a result of an extensive research, the present inventors havefound that 1) a glass coated with a heat reflecting colored film, whichcomprises a glass substrate, and a specific first layer and a specificsecond layer, laminated sequentially by a sputtering method on one sideof the glass substrate, is excellent in the uniformity of the filmthickness and composition and excellent in the heat reflectivity, andthat 2) a glass coated with a heat reflecting colored film obtained byheat treatment of such glass coated with a heat reflecting colored film,not only satisfies the basic required characteristics such that thesolar energy transmittance is low, the visible light transmittance ishigher than the solar energy transmittance, it has adequate durabilityfor e.g. a vehicle, it has a color tone which does not impair the designfor e.g. a vehicle, and the sheet resistance is high, but also isexcellent in the uniformity of the film thickness and composition, freefrom unfavorable whitish coloration in ceramic color printing andexcellent in coloration of silver printing, and thus have accomplishedthe present invention.

[0013] The present invention provides a glass coated with a heatreflecting colored film (hereinafter referred to also as “glass A coatedwith a heat reflecting colored film”), which comprises a glasssubstrate, and a first layer containing iron oxide and a second layercontaining cobalt oxide, laminated sequentially by a sputtering methodon one side of the glass substrate, wherein:

[0014] in the first layer, the amount of iron based on the total metalamount is at least 60 mass %, and in the second layer, the amount ofcobalt based on the total metal amount is at least 60 mass %.

[0015] Further, the present invention provides a glass coated with aheat reflecting colored film (hereinafter referred to also as “glass Bcoated with a heat reflecting colored film”), which comprises a glasssubstrate, and a first layer containing cobalt oxide and a second layercontaining iron oxide, laminated sequentially by a sputtering method onone side of the glass substrate, wherein:

[0016] in the first layer, the amount of cobalt based on the total metalamount is at least 60 mass %, and

[0017] in the second layer, the amount of iron based on the total metalamount is at least 60 mass %.

[0018] Further, the present invention provides a glass coated with aheat reflecting colored film (hereinafter referred to also as “glass Ccoated with a heat reflecting colored film”), which comprises a glasssubstrate, and a first layer containing iron oxide, chromium oxide andnickel oxide and a second layer containing cobalt oxide, laminatedsequentially by a sputtering method on one side of the glass substrate,wherein:

[0019] in the first layer, the amounts of iron, chromium and nickel,based on the total metal amount, are as follows:

[0020] iron: from 60 mass % to 85 mass %,

[0021] chromium: from 10 mass % to 28 mass %, and

[0022] nickel: from 5 mass % to 24 mass %, and

[0023] in the second layer, the amount of cobalt based on the totalmetal amount is at least 60 mass %.

[0024] Further, the present invention provides a glass coated with aheat reflecting colored film (hereinafter referred to also as “glass Dcoated with a heat reflecting colored film”), which comprises a glasssubstrate, and a first layer containing cobalt oxide and a second layercontaining iron oxide, chromium oxide and nickel oxide, laminatedsequentially by a sputtering method on one side of the glass substrate,wherein:

[0025] in the first layer, the amount of cobalt based on the total metalamount, is at least 60 mass %, and

[0026] in the second layer, the amounts of iron, chromium and nickel,based on the total metal amount, are as follows:

[0027] iron: from 60 mass % to 85 mass %,

[0028] chromium: from 10 mass % to 28 mass %, and

[0029] nickel: from 5 mass % to 24 mass %.

[0030] Further, the present invention provides a process for producingthe above-mentioned glass A coated with a heat reflecting colored film,which comprises:

[0031] a step of laminating the first layer on one side of the glasssubstrate, by sputtering by means of a metal oxide target containingiron oxide, and a step of laminating the second layer on the firstlayer, by sputtering by means of a metal target containing cobalt in asputtering gas atmosphere containing an oxidizing gas, or by sputteringby means of a metal oxide target containing cobalt oxide in a sputteringgas atmosphere containing no oxidizing gas or in a sputtering gasatmosphere containing an oxidizing gas.

[0032] Further, the present invention provides a process for producingthe above-mentioned glass B coated with a heat reflecting colored film,which comprises:

[0033] a step of laminating the first layer on one side of the glasssubstrate, by sputtering by means of a metal target containing cobalt ina sputtering gas atmosphere containing an oxidizing gas, or bysputtering by means of a metal oxide target containing cobalt oxide in asputtering gas atmosphere containing no oxidizing gas or in a sputteringgas atmosphere containing an oxidizing gas, and

[0034] a step of laminating the second layer on the first layer, bysputtering by means of a metal oxide target containing iron oxide.

[0035] Further, the present invention provides process for producing theabove-mentioned glass C coated with a heat reflecting colored film,which comprises:

[0036] a step of laminating the first layer on one side of the glasssubstrate, by sputtering by means of a metal target containing iron,chromium and nickel as components in a sputtering gas atmospherecontaining an oxidizing gas, and

[0037] a step of laminating the second layer on the first layer, bysputtering by means of a metal target containing cobalt in a sputteringgas atmosphere containing an oxidizing gas, or by sputtering by means ofa metal oxide target containing cobalt oxide in a sputtering gasatmosphere containing no oxidizing gas or in a sputtering gas atmospherecontaining an oxidizing gas.

[0038] Further, the present invention provides a process for producingthe above-mentioned glass D coated with a heat reflecting colored film,which comprises:

[0039] a step of laminating the first layer on one side of the glasssubstrate, by sputtering by means of a metal target containing cobalt ina sputtering gas atmosphere containing an oxidizing gas, or bysputtering by means of a metal oxide target containing cobalt oxide in asputtering gas atmosphere containing no oxidizing gas or in a sputteringgas atmosphere containing an oxidizing gas, and

[0040] a step of laminating the second layer on the first layer, bysputtering by means of a metal target containing iron, chromium andnickel as components in a sputtering gas atmosphere containing anoxidizing gas.

[0041] Further, the present invention provides a glass coated with aheat reflecting colored film (hereinafter referred to also as “glass Ecoated with a heat reflecting colored film”, obtained by heat treatmentof the above-mentioned glass A, B, C or D coated with a heat reflectingcolored film.

[0042] The above-mentioned glass E coated with a heat reflecting coloredfilm is preferably such that the surface sheet resistance of thefilm-coated side is at least 10⁵ Ω/□.

[0043] The above-mentioned glass E coated with a heat reflecting coloredfilm is preferably such that the visible light transmittance is from 20to 40%, and the visible light reflectance of the film-coated side andthe other side is from 20 to 40% and from 10 to 25%, respectively.

[0044] Further, the present invention provides a process for producingthe above-mentioned glass E coated with a heat reflecting colored film,which comprises:

[0045] a step of coating a ceramic color paste and/or a silver paste onthe above-mentioned glass A, B, C or D coated with a heat reflectingcolored film obtained by the process as defined in any one of theabove-mentioned processes, and

[0046] a step of then carrying out heat treatment.

BEST MODE FOR CARRYING OUT THE INVENTION

[0047] Now, the present invention will be described in detail.

[0048] Each of glasses A, B, C and D coated with a heat reflectingcolored film of the present invention, is a glass coated with a heatreflecting colored film, which comprises a glass substrate, and aspecific first layer and a specific second layer, laminated sequentiallyby a sputtering method on one side of the glass substrate. Now, glassesA, B, C and D coated with a heat reflecting colored film of the presentinvention, will be described.

[0049] The glass substrate to be used for glasses A, B, C and D coatedwith a heat reflecting colored film of the present invention, is notparticularly limited, and a commonly widely employed colorlesstransparent soda lime glass, a heat absorbing glass colored green,bronze, gray or the like, or a glass having a heat absorbing/ultravioletabsorbing property, may, for example, be employed. The first layer ofglass A coated with a heat reflecting colored film, contains iron oxide.In the present invention, in addition to iron oxide, chromium oxide,nickel oxide, niobium oxide, molybdenum oxide, manganese oxide, siliconoxide, copper oxide, vanadium oxide, zinc oxide, zirconium oxide,carbon, etc., may be contained within the range of the followingcomposition.

[0050] In the first layer of glass A coated with a heat reflectingcolored film, the amount of iron based on the total metal amount is atleast 60 mass %. The upper limit value is not particularly limited, andit may be used at most 100%. With a view to reducing the solar energytransmittance, it is preferably used in an amount of at least 90%,particularly at least 97%.

[0051] The thickness of the first layer of glass A coated with a heatreflecting colored film, can be selected depending upon the desiredoptical characteristics. For example, the thickness of the first layeris preferably adjusted to be from 3 to 15 nm, in a case where thevisible light transmittance of the glass coated with a heat reflectingcolored film of the present invention is made to be from 20 to 40%, andthe visible light reflectance of the film-coated side and the other sideis made to be from 20 to 40% and from 10 to 25%, respectively.

[0052] The second layer of glass A coated with a heat reflecting coloredfilm, contains cobalt oxide. In the present invention, in addition tothe cobalt oxide, niobium oxide, molybdenum oxide, manganese oxide,silicon oxide, copper oxide, vanadium oxide, zinc oxide, zirconiumoxide, carbon, etc., may be contained within the range of the followingcomposition.

[0053] In the second layer of glass A coated with a heat reflectingcolored film, the amount of cobalt based on the total metal amount, isat least 60 mass %. The upper limit value is not particularly limited,and it may be used in an amount of at most 100%. With a view to reducingthe solar energy transmittance, it is preferably used in an amount of atleast 90%, particularly at least 97%.

[0054] The thickness of the second layer of glass A coated with heatreflecting colored film, can be selected depending upon the desiredoptical characteristics. For example, the thickness of the second layeris preferably adjusted to be from 10 to 50 nm, in a case where thevisible light transmittance of the glass coated with a heat reflectingcolored film of the present invention is made to be from 20 to 40%, andthe visible light reflectance of the film-coated side and the other sideis made to be from 20 to 40% and from 10 to 25%, respectively.

[0055] With respect to the composition, the preferred thickness, etc.,the first layer of glass B coated with a heat reflecting colored film,is similar to the second layer of the above-mentioned glass A coatedwith a heat reflecting colored film.

[0056] With respect to the composition, the preferred thickness, etc.,the second layer of glass B coated with a heat reflecting colored film,is similar to the first layer of the above-mentioned glass A coated witha heat reflecting colored film.

[0057] The first layer of glass C coated with a heat reflecting coloredfilm, contains iron oxide, chromium oxide and nickel oxide. In thepresent invention, in addition to these oxides, niobium oxide,molybdenum oxide, manganese oxide, silicon oxide, copper oxide, vanadiumoxide, zinc oxide, zirconium oxide, carbon, etc., may be contained withthe range of the following composition.

[0058] From the viewpoint of the heat reflectivity and efficiency in thefilm formed by a magnetron sputtering method, in the first layer ofglass C coated with a heat reflecting colored film, the amounts of iron,chromium and nickel, based on the total metal amount, are such thatiron: from 60 mass % to 85 mass %, chromium: from 10 mass % to 28 mass%, and nickel: from 5 mass % to 24 mass %.

[0059] The thickness of the first layer of glass C coated with a heatreflecting colored film, can be selected depending upon the desiredoptical characteristics. For example, the thickness of the first layeris preferably adjusted to be from 3 to 15 nm, in a case where thevisible light transmittance of the glass coated with a heat reflectingcolored film of the present invention is made to be from 20 to 40%, andthe visible light reflectance of the film-coated side and the other sideis made to be from 20 to 40% and from 10 to 25%, respectively.

[0060] With respect to the composition, the preferred thickness, etc.,the second layer of glass C coated with a heat reflecting colored film,is similar to the second layer of the above-mentioned glass A coatedwith a heat reflecting colored film.

[0061] With respect to the composition, the preferred thickness, etc.,the first layer of glass D coated with a heat reflecting colored film,is similar to the second layer of the above-mentioned glass C coatedwith a heat reflecting colored film.

[0062] With respect to the composition, the preferred thickness, etc.,the second layer of glass D coated with a heat reflecting colored film,is similar to the first layer of the above-mentioned glass C coated witha heat reflecting colored film.

[0063] Further, in the present invention, for the purpose of e.g.improving the durability or changing the reflectance, a functional layerto accomplish such an object may be provided on the second layer,between the first layer and the glass substrate, or on the side oppositeto the side coated with the heat reflecting colored film.

[0064] As such a functional layer, a layer made of at least one elementselected from the group consisting of silicon, titanium, zinc, tin,copper, zirconium, manganese, niobium and aluminum, or an oxide ornitride of such an element, may be mentioned.

[0065] The glass coated with a heat reflecting colored film of thepresent invention, has a film construction which can be formed by asputtering method, whereby it is excellent in the uniformity of the filmthickness and composition.

[0066] In the processes for producing glasses A, B, C and D coated witha heat reflecting colored film of the present invention, theabove-described first layer and the above-described second layer may besequentially laminated by a sputtering method on one side of theabove-mentioned glass substrate, but they are particularly preferablycarried out as follows, in that conventional sputtering targets canthereby be employed. It should be understood that the followingprocesses are preferred embodiments, and the processes for producingglasses A, B, C and D coated with a heat reflecting colored film of thepresent invention, are not limited thereto.

[0067] (1) In the Case of Glass A Coated with a Heat Reflecting ColoredFilm

[0068] Glass A coated with a heat reflecting colored film is produced bya process which comprises:

[0069] a step of laminating the first layer on one side of the glasssubstrate, by sputtering by means of a metal oxide target containingiron oxide, and

[0070] a step of laminating the second layer on the first layer, bysputtering by means of a metal target containing cobalt in a sputteringgas atmosphere containing an oxidizing gas, or by sputtering by means ofa metal oxide target containing cobalt oxide in a sputtering gasatmosphere containing no oxidizing gas or in a sputtering gas atmospherecontaining an oxidizing gas.

[0071] As the metal oxide target to be used in the step of laminatingthe first layer, one containing iron oxide, is used. Particularlypreferred is one which contains iron oxide in an amount of from 60 to100 mass % as the amount of iron based on the total metal amount, inorder to bring the composition of the first layer as described above.

[0072] The sputtering gas may be one containing no oxidizing gas or maybe one containing an oxidizing gas.

[0073] The sputtering gas containing no oxidizing gas may, for example,be an inert gas such as helium, neon, argon, krypton or xenon. Amongthem, argon is preferred from the viewpoint of the economical efficiencyand ease of discharge. These inert gases may be used alone or incombination as a mixture of two or more of them.

[0074] The oxidizing gas may, for example, be oxygen or ozone, or it maybe a gas mixture of oxygen and ozone. As the sputtering gas containingan oxidizing gas, a gas mixture of such an oxidizing gas and theabove-mentioned inert gas, may be employed.

[0075] For the sputtering, a magnetron sputtering apparatus which isexcellent in the film forming speed, etc., is usually employed. However,a sputtering apparatus of a type wherein no magnetic field is used, mayalso be employed.

[0076] Further, as the power source, any of a direct current powersource, a power source for applying an electric power in pulses, analternate current power source and a high frequency power source, may beemployed.

[0077] As the target to be used for the step of laminating the secondlayer, a metal target containing cobalt, or a metal oxide targetcontaining cobalt oxide, is used. Particularly, in order to adjust thecomposition of the second layer as described above, when a metal targetcontaining cobalt is employed, it preferably contains cobalt in anamount of from 60 to 100 mass %, and when a metal oxide targetcontaining cobalt oxide is employed, it preferably contains cobalt oxidein an amount of from 60 to 100 mass % as the amount of cobalt based onthe total metal amount.

[0078] As the sputtering gas, one containing an oxidizing gas isemployed in the case where a metal target containing cobalt is employed.As the oxidizing gas, the above-mentioned one may be employed.

[0079] In a case where a metal oxide target containing cobalt oxide isemployed, the sputtering gas may be one containing no oxidizing gas, orone containing an oxidizing gas. As such an oxidizing gas, theabove-mentioned one may also be employed.

[0080] When either target is employed, a gas mixture comprising anoxidizing gas and an inert gas, may be employed.

[0081] The sputtering apparatus is the same as in the case f the processof laminating the first layer.

[0082] (2) In the Case of Glass B Coated with a Heat Reflecting ColoredFilm

[0083] Glass B coated with a heat reflecting colored film is produced bya process which comprises:

[0084] a step of laminating the first layer on one side of the glasssubstrate, by sputtering by means of a metal target containing cobalt ina sputtering gas atmosphere containing an oxidizing gas, or bysputtering by means of a metal oxide target containing cobalt oxide in asputtering gas atmosphere containing no oxidizing gas or in a sputteringgas atmosphere containing an oxidizing gas, and

[0085] a step of laminating the second layer on the first layer, bysputtering by means of a metal oxide target containing iron oxide.

[0086] The metal target, the sputtering gas and the sputtering apparatusto be used in the step of laminating the first layer, are the same as inthe case of the second layer in process (1).

[0087] The metal target, the sputtering gas and the sputtering apparatusto be used in the step of laminating the second layer, are the same asin the case of the first layer in process (1).

[0088] (3) In the Case of Glass C Coated with a Heat Reflecting ColoredFilm

[0089] Glass C coated with a heat reflecting colored film, is producedby a process which comprises:

[0090] a step of laminating the first layer on one side of the glasssubstrate, by sputtering by means of a metal target containing iron,chromium and nickel as components in a sputtering gas atmospherecontaining an oxidizing gas, and

[0091] a step of laminating the second layer on the first layer, bysputtering by means of a metal target containing cobalt in a sputteringgas atmosphere containing an oxidizing gas, or by sputtering by means ofa metal oxide target containing cobalt oxide in a sputtering gasatmosphere containing no oxidizing gas or in a sputtering gas atmospherecontaining an oxidizing gas.

[0092] The metal target to be used in the step of laminating the firstlayer is not particularly limited with respect to the composition orstructure. Among iron, chromium and nickel, two or more metals may forma single crystal phase or may be in the form of a solid solution.Otherwise, crystalline phases or non-crystalline phases of the above twoor more metals may be present in a mixed state, or masses of the abovetwo or more metals may be separately present, respectively. In thepresent invention, as the metal target, a metal target containing iron,chromium and nickel as components, is used from the viewpoint ofdischarge. Particularly in order to adjust the composition of the firstlayer a described above, one having the following composition ispreferred:

[0093] Iron: from 63 to 78 mass %,

[0094] Chromium: from 16 to 24 mass %, and

[0095] Nickel: from 6 to 13 mass %.

[0096] For example, a non-magnetic stainless steel, more specifically,an austenite type non-magnetic stainless steel as stipulated in JISG4304-1987, may be mentioned. Particularly preferred is SUS304.

[0097] As a preferred example for the target to be used in the step oflaminating the second layer, a Co target or a Co₃O₄ target may bementioned.

[0098] As the sputtering gas, one containing an oxidizing gas isemployed. The oxidizing gas is as described above. Further, a gasmixture comprising an oxidizing gas and an inert gas may be employed.

[0099] The apparatus to be used for the sputtering is the same as in thecase of the first layer in process (1).

[0100] The step of laminating the second layer is the same as in thecase of process (1).

[0101] (4) In the Case of Glass D coated with a Heat Reflecting ColoredFilm

[0102] Glass D coated with a heat reflecting colored film is produced bya process which comprises:

[0103] a step of laminating the first layer on one side of the glasssubstrate, by sputtering by means of a metal target containing cobalt ina sputtering gas atmosphere containing an oxidizing gas, or bysputtering by means of a metal oxide target containing cobalt oxide in asputtering gas atmosphere containing no oxidizing gas or in a sputteringgas atmosphere containing an oxidizing gas, and

[0104] a step of laminating the second layer on the first layer, bysputtering by means of a metal target containing iron, chromium andnickel as components in a sputtering gas atmosphere containing anoxidizing gas.

[0105] The metal target, the sputtering gas and the sputtering apparatusto be used in the process of laminating the first layer, are the same asin the case of the second layer in process (3).

[0106] The metal target, the sputtering gas and the sputtering apparatusto be used in the step of laminating the second layer, are the same asin the case of the first layer in process (3).

[0107] Glasses A, B, C and D coated with a heat reflecting colored filmof the present invention are excellent in the heat reflectivity.Specifically, the solar energy transmittance is preferably smaller thanthe visible light transmittance, particularly preferably at most 40%(more preferably at most 35%).

[0108] As described in the foregoing, glasses A, B, C and D coated witha heat reflecting colored film of the present invention are excellent inthe uniformity of the film thickness and composition, since they can beproduced by sputtering method. Further, they exhibit excellent eatreflectivity. Further, as described hereinafter, lasses A, B, C and Dcoated with a heat reflecting colored film of the present invention, aresuitably employed for the production of glass E coated with a heatreflecting colored film of the present invention.

[0109] Now, glass E coated with a heat reflecting colored glass of thepresent invention will be described.

[0110] The glass coated with a heat reflecting colored film of thepresent invention can be obtained by heat treatment of theabove-mentioned glass A, B, C or D coated with a heat reflecting coloredfilm.

[0111] By the heat treatment, the surface sheet resistance of thefilm-coated side will be improved, and the surface sheet resistance ofthe film-coated side will be preferably at least 10⁵ Ω/□, whereby theradio wave transmittance will be improved. Accordingly, it is suitablyemployed for vehicles or buildings.

[0112] Further, by the heat treatment, visible light reflectance of thefilm-coated side is decreased, preferably to a level of from 20 to 40%,which is a value suitable for vehicles.

[0113] The heat treatment is not particularly limited, and theconditions may be changed depending upon the desired opticalcharacteristics. As a preferred specific example, heat treatment may bementioned which is carried out at a temperature of from 500 to 700° C.for from 3 to 5 minutes in an atmosphere containing oxygen (such as theatmospheric air).

[0114] Glass E coated with a heat reflecting colored film of the presentinvention is suitably employed for e.g. vehicles such as automobiles.The glass to be used for e.g. vehicles such as automobiles, is subjectedto heat treatment in the atmosphere at a temperature of from 630 to 690°C. or higher for from 3 to 7 minutes in the case of bending treatment.Accordingly, glass E coated with a heat reflecting colored film of thepresent invention may be obtained by subjecting glass A, B, C or Dcoated with a heat reflecting colored film to bending treatment and byutilizing the heat treatment at that time.

[0115] Further, when silver printing or printing by means of a ceramiccolor paste such as a black ceramic coating material, is applied toglass A, B, C or D coated with a heat reflecting colored film of thepresent invention, heat treatment (baking) is carried out in theatmosphere at a temperature of from 630 to 690° C. or higher for fromabout 3 to 7 minutes. Accordingly, glass E coated with a heat reflectingcolored film of the present invention may also be obtained by applyingsilver printing or printing by means of a ceramic color paste to glassA, B, C or D coated with a heat reflecting colored film and utilizingthe heat treatment (baking) at that time.

[0116] Further, the bending treatment and silver printing or printing bymeans of a ceramic color paste, may be carried out simultaneously, andheat treatment at that time may be utilized.

[0117] Namely, the process for producing glass E coated with a heatreflecting colored film of the present invention may preferably be aprocess which comprises:

[0118] a step of coating a ceramic color paste and/or a silver paste onglass A, B, C or D coated with a heat reflecting colored film obtainedby any one of the above-mentioned processes (1) to (4), and

[0119] a step of then carrying out heat treatment.

[0120] Coating of the ceramic color paste and/or the silver paste can becarried out by a usual method. For example, a screen printing method bymeans of a screen printing machine may be mentioned. In a case whereboth the ceramic color paste and the silver paste are to be coated, theymay be separately coated or may be simultaneously coated.

[0121] The conditions for the heat treatment may be the same as in thecase where they are not coated.

[0122] The ceramic color paste may, for example, be one containingcrystalline glass frit (and/or non-crystalline glass frit), a heatresistant coloring pigment and a refractory filler. The ceramic colorpaste may, for example, be prepared by uniformly mixing the crystallineglass frit (and/or the non-crystalline glass frit), the heat resistantcoloring pigment and the refractory filler in an organic vehicle andadjusting the mixture to a viscosity suitable for coating.

[0123] As the silver paste, one having fine silver particles and glassfrit uniformly mixed to an organic vehicle, is adjusted to a viscositysuitable for coating.

[0124] Glass E coated with a heat reflecting colored film of the presentinvention, is excellent in the heat reflectivity. Specifically, thesolar energy transmittance is preferably smaller than the visible lighttransmittance, particularly preferably at most 40% (more preferably atmost 35%).

[0125] Glass E coated with a heat reflecting colored film of the presentinvention preferably has a surface sheet resistance of at least 10⁵ Ω/□on the film-coated side. If the surface sheet resistance is within theabove range, it is possible to secure adequate transmittance of radiowaves of e.g. radios, televisions, mobile phones or car phones in e.g.vehicles such as automobiles.

[0126] Further, when glass E coated with a heat reflecting colored filmof the present invention is employed as a rear window glass of anautomobile, the surface sheet resistance on the film-coated side ispreferably at least 10⁶ Ω/□.

[0127] Glass E coated with a heat reflecting colored film of the presentinvention is preferably such that the visible light transmittance isfrom 20 to 40%, and the visible light reflectance on the film-coatedside and the other side is from 20 to 40% and from 10 to 25%,respectively. Within the above ranges, glass E is suitable forapplication to e.g. automobiles.

[0128] Glass E coated with a heat reflecting colored film of the presentinvention is excellent in the uniformity of the film thickness andcomposition as compared with one prepared by a conventional spraymethod, since the colored film is formed by a sputtering method.

[0129] As is different from a conventional glass having formed by aspray method an oxide film comprising cobalt oxide as the maincomponent, at least 10 mass % of iron and at least 5 mass % of chromium,glass E coated with a heat reflecting colored film of the presentinvention is free from whitening or color forming failure when printingis applied by means of a ceramic color paste such as black ceramiccoating material, although the reason is not clearly understood.Further, as is different from a conventional glass having formed by aspray method an oxide film comprising cobalt oxide as the maincomponent, at least 10 mass % of iron and at least 5 mass % of chromium,glass E coated with a heat reflecting colored film is excellent incoloration of silver printing, although the reason is not clearlyunderstood.

[0130] Applications of glass E coated with a heat reflecting coloredfilm of the present invention are not particularly limited, but, forexample, applications for vehicles such as automobiles, or forbuildings, may be mentioned.

[0131] Further, the glass coated with a heat reflecting colored film ofthe present invention may be made into a laminated glass or a compositeglass.

[0132] Glass E coated with a heat reflecting colored film of the presentinvention is useful for various applications, since not only itsatisfies the basic required characteristics, but also it is excellentin the uniformity of the film thickness and composition, free fromunfavorable whitish coloration in ceramic color printing and alsoexcellent in coloration of silver printing.

EXAMPLES

[0133] Now, the present invention will be described in further detailwith reference to Examples, but the present invention is by no meansrestricted thereto.

[0134] 1. Preparation of Glass Coated with Heat Reflecting Colored Film

Example 1

[0135] A green-colored soda lime glass having a thickness of 3.5 mm andcut into a square of 100×100 mm, was washed with a cerium oxide powderand a neutral detergent and then rinsed with pure water and ethanol toobtain a substrate glass. The green-colored soda lime glass had avisible light transmittance of 81.6%, a visible light reflectance of7.4%, a solar radiation transmittance of 59.5% and a solar radiationreflectance of 6.2%.

[0136] On this substrate glass, a film (first layer) having a thicknessof 6 nm was formed by carrying out film forming by means of a DCmagnetron sputtering apparatus using a sputtering target of FeO (amountof iron based on the total metal amount: 99.9 mass %) having a diameterof 101.6 mm under such conditions that the Ar gas pressure was 4.8×10⁻¹Pa, the applied power was 0.3 kW and the film forming time was 6seconds.

[0137] Further, on that film, a film (second layer) having a thicknessof 30 nm was formed by carrying out film forming by means of a DCmagnetron sputtering apparatus using a sputtering target of Co₃O₄(amount of cobalt based on the total metal amount: 99.9 mass %) having adiameter of 101.6 mm under such conditions that the Ar gas pressure was4.8×10⁻¹ Pa, the applied power was 0.3 kW and the film-forming time was147 seconds, to obtain glass A coated with a heat reflecting coloredfilm of the present invention.

[0138] Then, a ceramic color paste and an electroconductive silver pastewere prepared to have viscosities suitable for screen printing. Then,the ceramic color paste was printed on the film-coated side of theobtained glass A having a heat reflecting colored film by a screenprinting machine and dried. Then, the electroconductive silver paste wasprinted by a screen printing machine. After drying at 120° C. for from10 to 15 minutes, heat treatment was carried out for about 15 minutes inthe atmospheric air by a belt furnace. The retention time at atemperature of at least 500° C. was about 6 minutes, and the retentiontime at the maximum temperature of 650° C. was about 3 minutes. Afterthe heat treatment, the treated product was left to cool to obtain glassE coated with a heat reflecting colored film of the present invention.

[0139] Here, the ceramic color paste used, was one prepared by mixing anamorphous glass frit, a heat resistant coloring pigment and a refractoryfiller uniformly to an organic vehicle, followed by adjusting themixture to a viscosity suitable for coating. Further, the employedelectroconductive silver paste was one prepared by mixing fine silverparticles and a glass frit uniformly with an organic vehicle, followedby adjusting the mixture to a viscosity suitable for coating.

Example 2

[0140] Glass B coated with a heat reflecting colored film of the presentinvention was obtained in the same manner as in Example 1 except thatthe order of film formation of the first and the second layers wasreversed. The thickness of the first layer was 30 nm, and the thicknessof the second layer was 6 nm.

[0141] Then, to the obtained glass B coated with a heat reflectingcolored film, printing and heat treatment were applied in the samemanner as in Example 1, and then the treated product was left to cool toobtain glass E coated with a heat reflecting colored film of the presentinvention.

Example 3

[0142] The same green-colored soda lime glass as in Example 1 having athickness of 3.5 mm and cut into a square of 100×100 mm, was washed witha cerium oxide powder and a neutral detergent, and then rinsed with purewater and ethanol to obtain a substrate glass.

[0143] On this substrate glass, a film having a thickness of 6 nm wasformed by carrying out film forming by means of a DC magnetronsputtering apparatus using a sputtering target of SUS304 stainless steel(iron: 74 mass %, chromium: 18 mass %, nickel: 8 mass %) having adiameter of 152.4 mm under such conditions that the O₂ gas pressure was2.6×10⁻¹ Pa, the applied power was 0.5 kW, and the film forming time was30 seconds.

[0144] Further, on that film, a film having a thickness of 30 nm wasprepared by carrying out film forming by means of a DC magnetronsputtering apparatus using a sputtering target of cobalt having athickness of 3 mm and a diameter of 152.4 mm under such conditions thatthe O₂ gas pressure was 2.6×10⁻¹ Pa, the applied power was 0.5 kW, andthe film-forming time was 150 seconds, to obtain glass C coated with aheat reflecting colored film of the present invention.

[0145] Then, to the obtained glass C coated with a heat reflectingcolored film, printing and heat treatment were applied in the samemanner as in Example 1. The obtained product was left to cool to obtainglass E coated with a heat reflecting colored film of the presentinvention.

Example 4

[0146] Glass D coated with a heat reflecting colored film of the presentinvention was obtained in the same manner as in Example 3 except thatthe order of film forming of the first and second layers was reversed.The thickness of the first layer was 30 nm and the thickness of thesecond layer was 6 nm.

[0147] Then, to the obtained glass D coated with a heat reflectingcolored film, printing and heat treatment were applied in the samemanner as in Example 1. Then, the treated product was left to cool toobtain glass E coated with a heat reflecting colored film of the presentinvention.

[0148] 2. Compositions of Coating Films in the Glasses Coated With HeatRay Reflecting Colored Films

[0149] In the above-mentioned production processes of Examples 1 to 4,the composition of the first layer was analyzed after formation of thefirst layer and before formation of the second layer, and thecomposition of the second layer was analyzed after formation of thesecond layer and before the heat treatment. The analyses of thecompositions were carried out by an elemental analysis by means of highfrequency inductively coupled plasma emission mass spectrometry.

[0150] As a result, in Example 1, the amount of iron based on the totalmetal amount in the first layer was 99.9 mass %, and the amount ofcobalt based on the total metal amount in the second layer was 99.9 mass%. In Example 2, the amount of cobalt based on the total metal amount inthe first layer was 99.9 mass %, and the amount of iron based on thetotal metal amount in the second layer was 99.9 mass %.

[0151] Further, in Example 3, the amounts of iron, chromium and nickel,based on the total metal amount in the first layer were 74 mass % ofiron, 18 mass % of chromium and 8 mass % of nickel, and the amount ofcobalt based on the total metal amount in the second layer, was 99.9mass %. In Example 4, the amount of cobalt based on the total metalamount in the first layer was 99.9 mass %, and the amounts of iron,chromium and nickel, based on the total metal amount in the second layerwere 74 mass % of iron, 18 mass % of chromium and 8 mass % of nickel,respectively.

[0152] 3. Measurement of the Solar Energy Transmittance

[0153] With respect to glasses A to D coated with heat reflectingcolored films, obtained in Examples 1 to 4, the solar energytransmittance (according to JIS R3106) was measured by means of aspectrometer (the spectrometer “UV-3100PC”, manufactured by ShimadzuCorporation).

[0154] As a result, the solar energy transmittance was at most 30%, ineach case.

[0155] Further, with respect to glass E coated with heat reflectingcolored films, obtained in Examples 1 to 4, the solar energytransmittance (according to JIS R3106) was measured by a spectrometer(spectrometer “UV-3100PC”, manufactured by Shimadzu Corporation).

[0156] As a result, the solar energy transmittance was 29% in each case.

[0157] 4. Measurement of the Surface Sheet Resistance

[0158] With respect to glass E coated with a heat reflecting coloredfilm, obtained in each of Examples 1 to 4, the surface sheet resistanceon the film-coated side was measured by means of a sheet resister.

[0159] As a result, the surface sheet resistance of the film-coated sidewas 1.0×10⁹ Ω/□ in each case.

[0160] 5. Measurements of Visible Light Transmittance and Visible LightReflectance

[0161] With respect to glass E coated with a heat reflecting coloredfilm obtained in each of Examples 1 to 4, the visible lighttransmittance (according to JIS R3106) and the visible light reflectance(according to JIS R3106) on the film-coated side and the other side,were measured by means of a spectrometer (spectrometer “UV-3100PC”,manufactured by Shimadzu Corporation) using light source C.

[0162] As a result, the visible light transmittance was 31% in eachcase, the visible light reflectance on the film-coated side was 36% ineach case, and the visible light transmittance on the other side was 21%in each case.

[0163] Further, the difference depending upon the measuring site inglass E coated with a heat reflecting colored film obtained in each ofExamples 1 to 4 was within. 0.5% in each case with respect to thevisible light transmittance, and within 0.5% in each case with respectto the visible light reflectance. On the other hand, with a sampleobtained by a conventional spray method, the difference depending uponthe measuring site was from 1 to 2% with respect to the visible lighttransmittance, and from 1 to 2 with respect to the visible lightreflectance. From this result, it is evident that the glass coated witha heat reflecting colored film of the present invention is excellent inthe uniformity of the film thickness and in the uniformity of thecomposition.

[0164] 6. Measurement of Scratch Resistance

[0165] With respect to glass E coated with a heat reflecting coloredfilm obtained in each of Examples 1 to 4, a Taber's abrasion test on thefilm-coated side was carried out in accordance with an abrasionresistance test of JIS R3212 by means of Taber's tester under acondition of 1000 rotations under a load of 4.9N, and the visible lighttransmittances before and after the Taber's abrasion test, werecompared.

[0166] As a result, the change in the visible light transmittance was+12% in each case, which is not higher than +20%, thus indicatingpractically adequate scratch resistance.

[0167] 7. Measurement of Chemical Resistance

[0168] Glass E coated with a heat reflecting colored film obtained ineach of Examples 1 to 4 was immersed in a 0.05 mol/l (50 mol/m³)sulfuric acid aqueous solution or a 0.1 mol/l (100 mol/m³) sodiumhydroxide aqueous solution, at room temperature of 20° C. for 24 hours,whereby the visible light transmittances and the visible lightreflectances of the film-coated side and the other side, before andafter the immersion in the aqueous solution, were compared.

[0169] As a result, with each glass E coated with a heat reflectingcolored film, the change in the visible light transmittance, or thechange in the visible light reflectance on the film-coated side and theother side, was smaller than 1%, in the case of employing the aqueoussulfuric acid solution or the aqueous sodium hydroxide solution.

[0170] 8. Measurements of the Color Tones of the Ceramic Color Print andthe Silver Print

[0171] With respect to glass E coated with a heat reflecting coloredfilm, obtained in each of Examples 1 to 4, the color tone from the glasssurface of the ceramic color paste portion, was measured by means of acolor meter. As a result, the color tone was L=39, a=7.5 and b=0.0 ineach case. This means that as compared with a case where a conventionalglass having formed by a spray method an oxide film comprising 63 mass %of cobalt, 26 mass % of iron and 11 mass % of chromium, color formationwas good with a color tone close to neutral with low brightness.

[0172] Further, with the glass having a film formed by a conventionalspray method, the silver paste portion forms an antique red color, andno good coloration can be obtained. Whereas, with the samples of thepresent invention, each formed a red brown color, and thus good colorformation was obtained.

INDUSTRIAL APPLICABILITY

[0173] Glasses A, B, C and D coated with heat reflecting colored filmsof the present invention can be prepared by a magnetron sputteringmethod. Especially, by the process for producing the glass coated with aheat reflecting colored film of the present invention, a conventionalsputtering target can be used, whereby the production is easy, and theproduct is excellent in the uniformity of the film thickness andcomposition.

[0174] Further, glass E coated with a heat reflecting colored film ofthe present invention which is obtained by heat treatment of the aboveglass A, B, C or D coated with a heat reflecting colored film, not onlysatisfies the basic required characteristics, but also is excellent inthe uniformity of the film thickness and composition, free fromunfavorable whitish coloration in ceramic color printing and excellentalso in the coloration of silver printing, and thus it is suitable as awindow glass for an automobile.

[0175] The entire disclosure of Japanese Patent Application No.2000-129278 filed on Apr. 28, 2000 including specification, claims andsummary is incorporated herein by reference in its entirety.

What is claimed is:
 1. A glass coated with a heat reflecting coloredfilm, which comprises a glass substrate, and a first layer containingiron oxide and a second layer containing cobalt oxide, laminatedsequentially by a sputtering method on one side of the glass substrate,wherein: in the first layer, the amount of iron based on the total metalamount is at least 60 mass %, and in the second layer, the amount ofcobalt based on the total metal amount is at least 60 mass %.
 2. A glasscoated with a heat reflecting colored film, which comprises a glasssubstrate, and a first layer containing cobalt oxide and a second layercontaining iron oxide, laminated sequentially by a sputtering method onone side of the glass substrate, wherein: in the first layer, the amountof cobalt based on the total metal amount is at least 60 mass %, and inthe second layer, the amount of iron based on the total metal amount isat least 60 mass %.
 3. A glass coated with a heat reflecting coloredfilm, which comprises a glass substrate, and a first layer containingiron oxide, chromium oxide and nickel oxide and a second layercontaining cobalt oxide, laminated sequentially by a sputtering methodon one side of the glass substrate, wherein: in the first layer, theamounts of iron, chromium and nickel, based on the total metal amount,are as follows: iron: from 60 mass % to 85 mass %, chromium: from 10mass % to 28 mass %, and nickel: from 5 mass % to 24 mass %, and in thesecond layer, the amount of cobalt based on the total metal amount is atleast 60 mass %.
 4. A glass coated with a heat reflecting colored film,which comprises a glass substrate, and a first layer containing cobaltoxide and a second layer containing iron oxide, chromium oxide andnickel oxide, laminated sequentially by a sputtering method on one sideof the glass substrate, wherein: in the first layer, the amount ofcobalt based on the total metal amount, is at least 60 mass %, and inthe second layer, the amounts of iron, chromium and nickel, based on thetotal metal amount, are as follows: iron: from 60 mass % to 85 mass %,chromium: from 10 mass % to 28 mass %, and nickel: from 5 mass % to 24mass %.
 5. A process for producing the glass coated with a heatreflecting colored film as defined in claim 1, which comprises: a stepof laminating the first layer on one side of the glass substrate, bysputtering by means of a metal oxide target containing iron oxide, and astep of laminating the second layer on the first layer, by sputtering bymeans of a metal target containing cobalt in a sputtering gas atmospherecontaining an oxidizing gas, or by sputtering by means of a metal oxidetarget containing cobalt oxide in a sputtering gas atmosphere containingno oxidizing gas or in a sputtering gas atmosphere containing anoxidizing gas.
 6. A process for producing the glass coated with a heatreflecting colored film as defined in claim 2, which comprises: a stepof laminating the first layer on one side of the glass substrate, bysputtering by means of a metal target containing cobalt in a sputteringgas atmosphere containing an oxidizing gas, or by sputtering by means ofa metal oxide target containing cobalt oxide in a sputtering gasatmosphere containing no oxidizing gas or in a sputtering gas atmospherecontaining an oxidizing gas, and a step of laminating the second layeron the first layer, by sputtering by means of a metal oxide targetcontaining iron oxide.
 7. A process for producing the glass coated witha heat reflecting colored film as defined in claim 3, which comprises: astep of laminating the first layer on one side of the glass substrate,by sputtering by means of a metal target containing iron, chromium andnickel as components in a sputtering gas atmosphere containing anoxidizing gas, and a step of laminating the second layer on the firstlayer, by sputtering by means of a metal target containing cobalt in asputtering gas atmosphere containing an oxidizing gas, or by sputteringby means of a metal oxide target containing cobalt oxide in a sputteringgas atmosphere containing no oxidizing gas or in a sputtering gasatmosphere containing an oxidizing gas.
 8. A process for producing theglass coated with a heat reflecting colored film as defined in claim 4,which comprises: a step of laminating the first layer on one side of theglass substrate, by sputtering by means of a metal target containingcobalt in a sputtering gas atmosphere containing an oxidizing gas, or bysputtering by means of a metal oxide target containing cobalt oxide in asputtering gas atmosphere containing no oxidizing gas or in a sputteringgas atmosphere containing an oxidizing gas, and a step of laminating thesecond layer on the first layer, by sputtering by means of a metaltarget containing iron, chromium and nickel as components in asputtering gas atmosphere containing an oxidizing gas.
 9. A glass coatedwith a heat reflecting colored film, obtained by heat treatment of theglass coated with a heat reflecting colored film as defined in claim 1.10. A glass coated with a heat reflecting colored film, obtained by heattreatment of the glass coated with a heat reflecting colored film asdefined in claim
 2. 11. A glass coated with a heat reflecting coloredfilm, obtained by heat treatment of the glass coated with a heatreflecting colored film as defined in claim
 3. 12. A glass coated with aheat reflecting colored film, obtained by heat treatment of the glasscoated with a heat reflecting colored film as defined in claim
 4. 13.The glass coated with a heat reflecting colored film according to claim9, wherein the surface sheet resistance of the film-coated side is atleast 10⁵ Ω/□.
 14. The glass coated with a heat reflecting colored filmaccording to claim 10, wherein the surface sheet resistance of thefilm-coated side is at least 10⁵ Ω/□.
 15. The glass coated with a heatreflecting colored film according to claim 11, wherein the surface sheetresistance of the film-coated side is at least 10⁵ Ω/□.
 16. The glasscoated with a heat reflecting colored film according to claim 12,wherein the surface sheet resistance of the film-coated side is at least10⁵ Ω/□.
 17. The glass coated with a heat reflecting colored filmaccording to claim 9, wherein the visible light transmittance is from 20to 40%, and the visible light reflectance of the film-coated side andthe other side is from 20 to 40% and from 10 to 25%, respectively. 18.The glass coated with a heat reflecting colored film according to claim10, wherein the visible light transmittance is from 20 to 40%, and thevisible light reflectance of the film-coated side and the other side isfrom 20 to 40% and from 10 to 25%, respectively.
 19. The glass coatedwith a heat reflecting colored film according to claim 11, wherein thevisible light transmittance is from 20 to 40%, and the visible lightreflectance of the film-coated side and the other side is from 20 to 40%and from 10 to 25%, respectively.
 20. The glass coated with a heatreflecting colored film according to claim 12, wherein the visible lighttransmittance is from 20 to 40%, and the visible light reflectance ofthe film-coated side and the other side is from 20 to 40% and from 10 to25%, respectively.
 21. A process for producing the glass coated with aheat reflecting colored film, which comprises: a step of coating aceramic color paste and/or a silver paste on the glass coated with aheat reflecting colored film obtained by the process as defined in claim5, and a step of then carrying out heat treatment.
 22. A process forproducing the glass coated with a heat reflecting colored film, whichcomprises: a step of coating a ceramic color paste and/or a silver pasteon the glass coated with a heat reflecting colored film obtained by theprocess as defined in claim 6, and a step of then carrying out heattreatment.
 23. A process for producing the glass coated with a heatreflecting colored film, which comprises: a step of coating a ceramiccolor paste and/or a silver paste on the glass coated with a heatreflecting colored film obtained by the process as defined in claim 7,and a step of then carrying out heat treatment.
 24. A process forproducing the glass coated with a heat reflecting colored film, whichcomprises: a step of coating a ceramic color paste and/or a silver pasteon the glass coated with a heat reflecting colored film obtained by theprocess as defined in claim 8, and a step of then carrying out heattreatment.